# Atomic Structure Test 1

Total Questions:50 Total Time: 60 Min

Remaining:

## Questions 1 of 50

Question:The density of neutron stars is of the order

$${10^3}kg/cc$$

$${10^6}kg/cc$$

$${10^9}kg/cc$$

$${10^{11}}kg/cc$$

## Questions 2 of 50

Question:The discovery of neutron becomes very late because

Neutrons are present in nucleus

Neutrons are highly unstable particles

Neutrons are chargeless

Neutrons do not move

## Questions 3 of 50

Question:Cathode rays have

Mass only

Charge only

No mass and charge

Mass and charge both

## Questions 4 of 50

Question:The size of nucleus is measured in

amu

Angstrom

Fermi

cm

## Questions 5 of 50

Question:What is the ratio of mass of an electron to the mass of a proton

01:02

01:01

1 : 1837

01:03

## Questions 6 of 50

Question:The number of electrons in an atom of an element is equal to its

Atomic weight

Atomic number

Equivalent weight

Electron affinity

## Questions 7 of 50

Question:Number of electrons in the outermost orbit of the element of atomic number 15 is

1

3

5

7

## Questions 8 of 50

Question:The atomic weight of an element is double its atomic number. If there are four electrons in $$2p$$ orbital, the element is

$$C$$

$$N$$

$$O$$

$$Ca$$

## Questions 9 of 50

Question:The atomic number of an element is always equal to

Atomic weight divided by 2

Number of neutrons in the nucleus

Weight of the nucleus

Electrical charge of the nucleus

## Questions 10 of 50

Question:Which of the following is isoelectronic with carbon atom

$$N{a^ + }$$

$$A{l^{3 + }}$$

$${O^{2 - }}$$

$${N^ + }$$

## Questions 11 of 50

Question:The number of electrons and neutrons of an element is 18 and 20 respectively. Its mass number is

17

37

2

38

## Questions 12 of 50

Question:Number of protons, neutrons and electrons in the element $$_{89}^{231}Y$$ is

89, 231, 89

89, 89, 242

89, 142, 89

89, 71, 89

## Questions 13 of 50

Question:The number of electrons in $$C{l^ - }$$ ion is

19

20

18

35

## Questions 14 of 50

Question:The number of neutron in tritium is

1

2

3

0

## Questions 15 of 50

Question:Positronium consists of an electron and a positron (a particle which has the same mass as an electron, but opposite charge) orbiting round their common centre of mass. Calculate the value of the Rydberg constant for this system.

$${R_\infty }/4$$

$${R_\infty }/2$$

$$2{R_\infty }$$

$${R_\infty }$$

## Questions 16 of 50

Question:When $$\alpha$$-particles are sent through a thin metal foil, most of them go straight through the foil because (one or more are correct)

Alpha particles are much heavier than electrons

Alpha particles are positively charged

Most part of the atom is empty space

Alpha particles move with high velocity

## Questions 17 of 50

Question:When $$\beta$$-particles are sent through a tin metal foil, most of them go straight through the foil as

$$\beta$$-particles are much heavier than electrons

$$\beta$$-particles are positively charged

Most part of the atom is empty space

$$\beta$$-particles move with high velocity

## Questions 18 of 50

Question:The energy of second Bohr orbit of the hydrogen atom is -328 kJ mol $$^{ - 1}$$, hence the energy of fourth Bohr orbit would be

41 kJ mol $$^{ - 1}$$

1312 kJ mol $$^{ - 1}$$

164 kJ mol $$^{ - 1}$$

82 kJ mol $$^{ - 1}$$

## Questions 19 of 50

Question:The $$\alpha$$-particle scattering experiment of Rutherford concluded that

The nucleus is made up of protons and neutrons

The number of electrons is exactly equal to number of protons in atom

The positive charge of the atom is concentrated in a very small space

Electrons occupy discrete energy levels

## Questions 20 of 50

Question:Wavelength associated with electron motion

Increases with increase in speed of electron

Remains same irrespective of speed of electron

Decreases with increase in speed of $${e^ - }$$

Is zero

## Questions 21 of 50

Question:Rutherfordâ€™s a-particle scattering experiment proved that atom has

Electrons

Neutron

Nucleus

Orbitals

## Questions 22 of 50

Question:Wavelength of spectral line emitted is inversely proportional to

Energy

Velocity

Quantum number

## Questions 23 of 50

Question:The ratio of area covered by second orbital to the first orbital is

1:2

1:16

8:1

16:1

## Questions 24 of 50

Question:Time taken for an electron to complete one revolution in the Bohr orbit of hydrogen atom is

$$\frac{{4{\pi ^2}m{r^2}}}{{nh}}$$

$$\frac{{nh}}{{4{\pi ^2}mr}}$$

$$\frac{{nh}}{{4{\pi ^2}m{r^2}}}$$

$$\frac{h}{{2\pi mr}}$$

## Questions 25 of 50

Question:Which of the following expressions gives the de-Broglie relationship

$$h = \frac{\lambda }{{mv}}$$

$$\lambda = \frac{h}{{mv}}$$

$$\lambda = \frac{m}{{hv}}$$

$$\lambda = \frac{v}{{mh}}$$

## Questions 26 of 50

Question:de-Broglie equation is

$$n\lambda = 2d\sin \theta$$

$$E = hv$$

$$E = m{c^2}$$

$$\lambda = \frac{h}{{mv}}$$

## Questions 27 of 50

Question:The uncertainty principle was enunciated by

Einstein

Heisenberg

Rutherford

Pauli

## Questions 28 of 50

Question:According to heisenberg uncertainty principle

$$E = m{c^2}$$

$$\Delta x \times \Delta p \ge \frac{h}{{4\pi }}$$

$$\lambda = \frac{h}{p}$$

$$\Delta x \times \Delta p = \frac{h}{{6\pi }}$$

## Questions 29 of 50

Question:The uncertainty in momentum of an electron is $$1 \times {10^{ - 5}}kg\,m/s$$. The uncertainity in its position will be $$(h = 6.63 \times {10^{ - 34}}Js)$$

$$5.28 \times {10^{ - 30}}m$$

$$5.25 \times {10^{ - 28}}m$$

$$1.05 \times {10^{ - 26}}m$$

$$2.715 \times {10^{ - 30}}m$$

## Questions 30 of 50

Question:According to Heisenberg's uncertainty principle, the product of uncertainties in position and velocities for an electron of mass $$9.1 \times {10^{ - 31}}kg$$ is

$$2.8 \times {10^{ - 3}}{m^2}{s^{ - 1}}$$

$$3.8 \times {10^{ - 5}}{m^2}{s^{ - 1}}$$

$$5.8 \times {10^{ - 5}}{m^2}{s^{ - 1}}$$

$$6.8 \times {10^{ - 6}}{m^2}{s^{ - 1}}$$

## Questions 31 of 50

Question:Principal quantum number of an atom represents

Size of the orbital

Spin angular momentum

Orbital angular momentum

Space orientation of the orbital

## Questions 32 of 50

Question:An element has the electronic configuration $$1{s^2},2{s^2}2{p^6},3{s^2}3{p^2}$$. Its valency electrons are

6

2

3

4

## Questions 33 of 50

Question:A completely filled $$d$$-orbital $$({d^{10}})$$

Spherically symmetrical

Has octahedral symmetry

Has tetrahedral symmetry

Depends on the atom

## Questions 34 of 50

Question:If magnetic quantum number of a given atom represented by -3, then what will be its principal quantum number

2

3

4

5

## Questions 35 of 50

Question:The type of orbitals present in $$Fe$$ is

$$s$$

$$s$$ and $$p$$

$$s,\,p$$ and $$d$$

$$s,\,p,\,d$$ and $$f$$

## Questions 36 of 50

Question:The shape of $${d_{xy}}$$ orbital will be

Circular

Dumb-bell

Double dumb-bell

Trigonal

## Questions 37 of 50

Question:Ions which have the same electronic configuration are those of

Lithium and sodium

Sodium and potassium

Potassium and calcium

Oxygen and chlorine

## Questions 38 of 50

Question:When the azimuthal quantum number has a value of $$l = 0$$, the shape of the orbital is

Rectangular

Spherical

Dumbbell

Unsymmetrical

## Questions 39 of 50

Question:The azimuthal quantum number is related to

Size

Shape

Orientation

Spin

## Questions 40 of 50

Question:The total number of electrons that can be accommodated in all the orbitals having principal quantum number 2 and azimuthal quantum number 1 is

2

4

6

8

## Questions 41 of 50

Question:The set of quantum numbers not applicable for an electron in an atom is

$$n = 1,\,l = 1,\,{m_l} = 1,\,{m_s} = + 1/2$$

$$n = 1,\,l = 0,\,{m_l} = 0,\,{m_s} = + 1/2$$

$$n = 1,\,l = 0,\,{m_l} = 0,\,{m_s} = - 1/2$$

$$n = 2,\,l = 0,\,{m_l} = 0,\,{m_s} = + 1/2$$

## Questions 42 of 50

Question:Correct configuration of $$F{e^{ + 3}}$$ [26] is

$$1{s^2},2{s^2}2{p^6},3{s^2}3{p^6}3{d^5}$$

$$1{s^2},2{s^2}s{p^6},3{s^2}3{p^6}3{d^3},4{s^2}$$

$$1{s^2},2{s^2}2{p^6},3{s^2}3{p^6}3{d^6},4{s^2}$$

$$1{s^2},2{s^2}2{p^6},3{s^2}3{p^6}3{d^5},4{s^1}$$

## Questions 43 of 50

Question:For the $$n = 2$$ energy level, how many orbitals of all kinds are possible

2

3

4

5

## Questions 44 of 50

Question:When the principal quantum number $$(n = 3)$$, the possible values of azimuthal quantum number ($$l$$) is

0, 1, 2, 3

0, 1, 2

2, â€“ 1, 0, 1, 2

1, 2, 3

0, 1

## Questions 45 of 50

Question:What is the maximum number of electrons which can be accommodated in an atom in which the highest principal quantum number value is 4

10

18

32

54

## Questions 46 of 50

Question:Electronic configuration$$1{s^2},\,2{s^2}2{p^6},\,3{s^2}3{p^6}3{d^5},\,4{s^1}$$ represents

Ground state

Excited state

Anionic state

All of these

## Questions 47 of 50

Question:The number of electrons which can be accommodated in an orbital is

One

Two

Three

Four

## Questions 48 of 50

Question:$$3{d^{10}}4{s^0}$$ electronic configuration exhibits by

$$Z{n^{ + + }}$$

$$C{u^{ + + }}$$

$$C{d^{ + + }}$$

$$H{g^{ + + }}$$

## Questions 49 of 50

Question:The number of unpaired electrons in $$F{e^{3 + }}(Z = 26)$$ are

5

6

3

4

## Questions 50 of 50

Question:Electron enters the sub-shell for which $$(n + l)$$ value is minimum. This is enunciated as